/Engine/Source/Editor/UnrealEd/Public/Kismet2/BlueprintEditorUtils.h
Adds a member variable to the blueprint. It cannot mask a variable in any superclass.
true if it succeeds, false if it fails.
static bool AddMemberVariable ( [UBlueprint](API\Runtime\Engine\Engine\UBlueprint) * Blueprint, const [FName](API\Runtime\Core\UObject\FName) & NewVarName, const [FEdGraphPinType](API\Runtime\Engine\EdGraph\FEdGraphPinType) & NewVarType, const [FString](API\Runtime\Core\Containers\FString) & DefaultValue )